GoodSoundClub - Romy the Cat's Audio Site

Horn-Loaded Speakers
Topic: MacondoLite

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Posted by decoud on 08-15-2009

Here is a homage to the Macondo, or at least two channels of it - 400Hz tractrix with S2 and a 140Hz tractrix with Fane 8M. A T350 for HF and an as yet undefined LF solution is to be added. The horns are from Stereo Lab, with the larger horn reinforced with heavy plaster embedded in manila rope as armature.

Romy, may I ask for your suggestions for what crossovers to use for optimizing a) the MF alone b) the upper bass alone and c) the two together?

Posted by Romy the Cat on 08-15-2009

Decoud, in order to say anything useful I would like to know to the following:

1) Where the tweeter will be installed?
2) What the size of the room?
3) What are you planning to install the speaker in your room?
4) What LF solution do you consider?
5) What diaphragm you use in S2
6) How are you planning to drive the speaker
7) How you crossover it now and what is your current complains about sound in context of a single well know recording Let take the Beethoven V by Carlos Kleiber and Vieanna.
8) Can you post more pictures from side and from front at ear level?
9) How far are you planning to sit from your speaker?
10) Do you have RTA and Phase tester?

The Cat

Posted by decoud on 08-15-2009

Hi Romy,

Many thanks: the answers are...

1. The tweeter I thought could go below the MF.
2. The room is 5m x 5m x 3.6m.
3. Given size of room, corner location would be most practical.
4. LF will have to be compact, hence tapped horn appeals.
5. S2 diaphragm is metal surround.
6. Currently a 845 SET, next full range melquiades copy if unsatisfactory.
7. The thing has just been built: have not tried any cross-over with it yet.
8. The positioning is adjustable in vertical plane: will post more pictures shortly.
9. Listening position is 3 metres or so.
10. I have a phase tester, about to obtain an RTA.

Rgds, d

Posted by decoud on 08-15-2009
fiogf49gjkf0d Apologies for blurredness: room is very dark hence long exposure times. At listening level. Note the driver is off, hence light at the centre. Side view. Note the larger horn can move in the horizonal plane to time-align it with the S2. Back chamber is too big by design: removable MDF "spacers" allow volume adjustment.

Posted by mjloudspeaker on 08-15-2009
fiogf49gjkf0d Excellent idea and very good effort, I like it. j

Posted by Romy the Cat on 08-15-2009

decoud wrote:
The tweeter I thought could go below the MF.

Not going to work properly. The EV T350 is 120 by 60 degree tweeter met to work in vertical configuration. If I were you I would lower you MF until it edge along with upperbass and put the tweeter atop of MF, letting it to breathe

decoud wrote:
S2 diaphragm is metal surround.

This might be a subject of a major consideration. The 400Hz horn is in my view is a good solution for plastics suspended S2 as with 3uF cap you have the S2 secondary resonance in the band-pass it is work very good from 1000Hz and up. The diaphragm with metal surround has useable 2dB more and more or less flat down to 500Hz. However, you will not able to use it down to 500Hz as you have too small horn. If I use metal surround cone then I would go for 300Hz horn as it will be deeper, take advantage of the S2 lower range and by the virtue of being deeper it would do a minor low-passing of s2. With metal surround S2 you need to watch granularity of the S2 upper range as it has a tendency to be a bit “dirty staccato”. Connect the S2 with let say 15uF cap that will give you approximately 1K crossover point with metal surround and spend a few days listing the driver as it. Clean the driver and center it, play with loading of your amp - you shall find a configuration where you S2’s upper range in your 400Hz horn will be clean. It might have VERY MINOR grains but not annoying and very minor. Do not forget that the caps that you will be using for S2 high-passing will need a week or so to be able to clear up the S2 upper range. Until you confirm for yourself that you are satisfy with upper-region of your MF driver with metal surround I would ad do not think about crossovering too much.

So, do not use upperbass and do not use tweeter for now. If you wish you might use upperbass wide open for now. The sound of the S2 upper range, let say above 5K shall be the prime attention. One more thing. If for whatever reason you like or do not like S2 upper range as you have now then try to describe and post what you like or do not like as wordy and as detailed as you can. It is VERY important as it would suggest HOW to deal with it if you do not like it.

The caT

Posted by decoud on 08-16-2009
fiogf49gjkf0d Many thanks, Romy, will try it out and report back in a week or so. Regarding using a rack as a frame: it is good for prototyping as it is so flexible. Indeed, even aluminium is fine, because one can mass load it simply by mounting a 2U or 3U case filled with ballast.

Posted by RonyWeissman on 08-18-2009
fiogf49gjkf0d Hi, can you tell me(us) how much you pay'd for the mid-bass horn please? I may try this myself as I have been waiting six years now for a 15" midbass horn plan that is suitable with no luck ... thanksr weissman ps. Oh sorry I just found the price page on their website, I'll follow the thread to see how you like them. thanks

Posted by decoud on 08-18-2009

I should point out that my experience might not be representative because my horn is wrapped in 1 and 1/2 inch diameter manila rope and then doused in high density plaster, so it weights about 50kg or so. A simpler solution might be their "ultrafi" version which is double the price and about 5 times the weight, but its damping would be different from the strange combination of organic rope and plaster.

Posted by mjloudspeaker on 08-18-2009

decoud

The stereo lab store prices seem very reasonable, considering the cost and work of molds making, shipping is something else altogether, another factor yet, but my question always comes back to the tractrix curve, there is always a loss at the bottom, and I will stay tuned and read up on what you can extend your driver down to, without getting into "muffling the horn with chocking sound- quote copyright romy the cat".

Have you loaded up the True RTA Real Time Audio Spectrum Analyzer by John L. Murphy?

I am very curious about your findings regarding the 140 Hz spec. Because I am looking at all options for the community m4 driver, before commencing this trip, and tractrix is supposedly the "best curve", but my, my, it is quite large for this guy's smaller room. Upright horn seems right, it seems. Time alignment nightmare this upright may be, I think.

Try it decoup, the RTA, even the free version is very easy to use, and your ears can tell you plenty, a microphone response curve can follow later. The only thing, be aware of room modes, they might surprise you, and do not blame the beautiful horn prematurely, move them around on the ingenious rack.

Continue your fine work, I am a fan already.

RTA at http://www.trueaudio.com/

Posted by ayebee on 08-19-2009

I have also been working on a pair of Macondo-inspired horn-speakers. Horns from Stereo Lab, but with horn-drivers from JBL, rather than the elusive Vitavox. I hold Romy's forum in very high regard because of the content-standard of the posted messages. In order to not litter the forums with "moronic" questions about how to achieve the best sound from my horns I haven't posted any questions on this subject - although I must say I have quite a few. When I read decoud's post I felt that there might be some potential interest in "Macondo-cloning"-related discussion on this forum after all. Maybe in this thread?

/Ayebee

Posted by ayebee on 08-19-2009

The horns that Stereo Lab make are very good, especially considering the relatively modest prices. I bought the "Ultra-Fi" version of the 140Hz horns and they are of course not completely free of resonance - JLH's and Romy's massive horns are certainly in another league, I assume - but for the price they certainly are very good.

Present system consists of:
140Hz (3" throat) horn with Fane Sovereign 6" driver (120-700Hz)
250Hz horn with JBL 2440 driver (700Hz-2kHz)
600Hz horn with JBL 2420 driver (2-12kHz)

Bass is one Scan-Speak 8555 8-incher per channel in closed boxes. Quite insufficient.

I have a pair of EV 350's which aren't yet in use.

The motor of the Fane driver is too weak, and crossover is far from finished. The sound is showing a lot of promise, though.

...no affiliations with Stereo Lab, of course.

/ayebee

Posted by Romy the Cat on 08-19-2009

ayebee wrote:

The horns that Stereo Lab make are very good, especially considering the relatively modest prices. I bought the "Ultra-Fi" version of the 140Hz horns and they are of course not completely free of resonance ….

Present system consists of:
140Hz (3" throat) horn with Fane Sovereign 6" driver (120-700Hz)
250Hz horn with JBL 2440 driver (700Hz-2kHz)
600Hz horn with JBL 2420 driver (2-12kHz)
Bass is one Scan-Speak 8555 8-incher per channel in closed boxes. Quite insufficient.

I have a pair of EV 350's which aren't yet in use.

I do like the moves.

The 140Hz horn with 120-700Hz crossover. The decisions to have 3" throat was great – this horn will be loaded all the way to the bottom knee properly. I would not worry at this point about resonances, I more concerned about the wrong shape of the StereoLab’s upperbass horn’s back edge of mouth. I do not know Fane Sovereign. Look for 4’-6’ drivers with resonance frequency of 80-120Hz and low exertion. You will find a lot of them but very few of them will have high sensitivity. To find the right driver will be pain in ass. BTW, if you would like to rise then you might pick on eBay one “my” Fane Studio 8M. I think it is too big for 3” throat but you still never know how the driver will behave until you load it. If you run this channel up to 100Hz -1200Hz then I would not advise it but if you need to get from it just 600-700Hz then it might work. You will need to make absolutely minimum back chamber and to try it. It has true 103dB and with the huge frond chamber you might pick might be even 7dB in this horn. With this heavy load and with ultra-small back chamber you might not even need to high-pass the driver. Sure, a good 4” would be more fun but it might take for you forever to find it.

The 250Hz horn with JBL 2440 driver at 700Hz-2kHz. Interesting move with 2440. My only concern is that if you go with first order at this driver then it will be too identifiable as sourer and will offset your next channel too much. What I would experimenting be dropping crossover point on this china to lover, let say down to 1.5K and go with second or third low-pass order. The idea of using the bottom knee of 2440 is good idea but you do not want your 700Hz-2kHz suck out a vertical cender image from your MF. Go get a digital crossover, connect it to your 700Hz-2kHz channel and play with it trying to found out how much max low-pass you room/distance will be able to afford. The 2440 in this region is absolutely obedient and it will allow you to cross it wherever you wish. One more thing, if you found that you 2440 channel can handle no more then let say 1500kHz (the number is purely random) then pay attention at what dB lever it would be. You might always drop 3dB (or much more) in your 2440 channel and add some output by “opening up” the upper range of your 120-700Hz channel. You shall not be afraid to run the sub 1000Hz channels in acoustic parallel. This is one of the “secret” weapons of this configuration – you can add “room loading” with your upperbass and lover MF without affecting anything. Do not forget that your 700Hz-2kHz and your 120-700Hz channels will be on opposite side of highly directorial MF – so you might do whatever you want on trim of acoustic coupling of their outputs.

The 600Hz horn with JBL 2420 at 2-12kHz. Again a good move. The 2420 is 1” version of 2440. It has thinner sound “full-range”, but since you killed the bottom 1-2 octave it is a very good choice. The horn is shallow, the dispersion is wide, and the HF attenuation in throe is very low. With good selection of the 2420 diaphragms you might get very good result. With this configuration you will be able to try any driver of your chose – anything will work in there. The only “thing” that I envision will be a conflict between your desire to have your 2420 to crossed lower (to save imaging) and your desire to have 2440 to crossed higher. Well, you need to interstate this subject.

The Bass and tweeter channels are not important now. If you use EV 350 then do not use first order with them. It would be interesting see with what kind of frame you came up for your 3 horns assembly.

The caT

Posted by scooter on 08-19-2009

ayebee wrote:

Present system consists of:
140Hz (3" throat) horn with Fane Sovereign 6" driver (120-700Hz)
250Hz horn with JBL 2440 driver (700Hz-2kHz)
600Hz horn with JBL 2420 driver (2-12kHz)

Bass is one Scan-Speak 8555 8-incher per channel in closed boxes. Quite insufficient.

I have a pair of EV 350's which aren't yet in use.

The motor of the Fane driver is too weak, and crossover is far from finished. The sound is showing a lot of promise, though.

...no affiliations with Stereo Lab, of course.

/ayebee

Ayebee,

This is an interesting post. Could you speak a bit about your thought process with respect your choice of horns and drivers?

Also, it would be interesting to hear about your progress on crossovers to date, especially relating to your initial strategy and what has not worked according to plan and what are your next steps.

Thanks,

scooter

Posted by ayebee on 08-20-2009

The system is still very much a work in progress, but I have come to the conclusion that the concept as such is very, very good. It's only up to me to make it sound as well as I know it is capable of. Making and fine-tuning the crossover might take me a few years, but I can live with that.

I chose a 3” throat on the 140Hz horn for the exact reason that Romy points out. I wanted the horn to work as a horn with a minimum of direct radiation from the driver. Apparently, using 4” throats on 140Hz Tractrix-horns seems to work in real life. Maybe I was too “ambitious” in my choice, since the 3” throat might disqualify using 8” drivers, but maybe I should try the Fane 8M anyway – I have a pair in stock. The present Fane-driver I do not recommend, it has decent sensitivity, but the highish Qts (0,47) is not suitable to horn loading, resulting in a (relatively) dull and slow sound. I have recently found the 18-sound 6NMB420 which might fit the bill – but as Romy points out, the search might take some time.

The 2440 is a fine driver, but my experiments so far indicate that it can’t be used “full-range” in a home-environment. The 2440 on it’s own in the 250Hz-horn (44 cm diam) with no low-pass filtering was in no way a pleasant experience – very unsophisticated and harsh. I will definitely try using it in an even narrower range. Still – in the present range it has a very positive effect on sound. I’m not very good at describing my sonic impressions in words, so I’ll just say that getting the fundamentals-range right seems very critical in obtaining good sound.

I agree with Romy’s observation that the 2420 is a far more delicate sounding driver than the 2440. I tried using the 140Hz horn together with just the 2420 on a 400Hz horn (down to ca 1200Hz). This led to fine results, but the sound was miniaturized and less robust and "rustic" compared to the 2440-injected alternative. I want to use the horns well above their cut-off frequencies, and I probably need to use the 2440 a bit higher up in order to get rid of all horn colourations, though. These are probably my only real conclusions so far: “don’t push your horns” and “ it’s important to get the fundamentals range right”.

Crossovers are all first order, speaker level. I have a 1/3 octave RTA as a guide when trying out different values. Of course, my testing so far has been quite haphazard, and my knowledge is a bit limited, so I don’t want anyone to take this for anything more than amateurish ramblings. There are so many factors at play... Still, my experiences so far indicate that this might end up as a very satisfying project. DSET seem almost mandatory in this context, and this will be the next step once I have decided on rough crossover points.

And the frame? At the moment I’m just using open book-shelves from IKEA. I haven’t come up with a better alternative yet, but since I have decided on the horns and drivers, and in what vertical order they will be mounted, it’s “only” a matter of engineering.

/Ayebee

Posted by Romy the Cat on 08-21-2009

It is very important for the people who consider Macondo cloning is to understand what Macondo is all about. For a superficial or an idiot observer Macondo is the selections of drivers, horns, loading patterns and perhaps amplifiers. In really those selections and most of those decisions are not relay relevant for what Macondo is all about.

If you read careful the Macondo Page at http://www.romythecat.com/MacondoAcousticSystem.aspx then you read:

“What is also important to mention is that Macondo Acoustic System is not a design that I advocate as a “winning design” (though I do have a lot of convictions about it). The Macondo concept is not the collection of drivers, horns and frames; it is not the specific implementation – you will not be able to see what Macondo System is all about until you understand the correlation between what it meant to do and what it does. The Macondo System is rather a concept, a winning sequence of conscious ceremonial realizations and actions that lead a person from taking a room and converting it into a sensible and involved medium of musical intercourse.”

So, Macondo Cloning is not about building some kind of playback installation that visually of design-wise would mimic what I get but rather embracing PROPER and OBJECTIVE sound assessing techniques and make them a navigation tool in designing your acoustic system. Some of you (those few who has brain and senses) might be surprised eventually that if you embrace the front-loaded spherical horns topology and if you apply proper, meaningful and objective sound evaluation techniques then you accidently will end up with something that will be VERY similar to what I end up with my Macondo. Unfortunately there are no other ways to render this topology properly. Some of you might feel that I am too self-centric in my topology analyses but understanding will come to you, if you push it hard enough.

So, in the idea of Macondo Cloning there are truly no Cloning aspects. Similarly in the concept of Macondo-Light there is not truly Light ingredient. The proper, meaningful and objective sound evaluation techniques have no stratification for light and heavy and the decisions you will be making are absolutely disassociated from the concepts of “Light” or “Heavy”. Furthermore you do “clone” anything but you design your own speakers, perhaps using some pre-developed paths and pre-investigated patterns. I do the same and it has nothing to do with Cloning,

I have to mention that I have seen some idiots who did just Macondo cloning part, without applying own awareness as they have no personal consciousness. They snatched my drivers, they read 3432 times each post at this site and they put the channels in the arrangement that they understand as Macondo-like. In reality they are no different than monkey waving its hands. A monkey waves it hands because it is trying to hit bananas from trees but some idiots see in those hands waving an orchestra conducting. It is no surprise that two cloning attempts that I know ended up with garbage results –any techniques in the hands of barbarian will lead and have led to barbarian results.

The caT.

Posted by mjloudspeaker on 08-21-2009

Thank you Romy for saying this very important statement about Macondo topology. I believe that this is very very important and imperative for your numerous readership to "get this."

I, for one, have no intention whatsoever of copying your efforts, and I still enormously enjoy your site. I like to see what goes on in the "leading edge of audio" because it is on this site, and some others, that audio "things" are explored in much more depth, and for many more very deep and selfish reasons.

And I absolutely agree with your opinion that in very many senses, your system is not a "winning design", (way too complex, intricate, expensive, and electricity goblbing in this day), but why should it be? It is your design for your interests, and am I to understand they are quite selfish? Well, so are mine, and there can not be a "right and wrong way", because it there was, there would be one system for sale in the world, to meet this "perfect sound".

Quote- "The Macondo System is rather a concept, a winning sequence of conscious ceremonial realizations and actions that lead a person from taking a room and converting it into a sensible and involved medium of musical intercourse.”

For example, I've heard the great and expensive systems at IMAX theatres both in Sudbury and Montreal (these are Canadian cities) and these very comprehensive audio attempts were atrocious to me, a huge waste of money, for sure. My attempt in my studio (built from 1988 to 1992) made the IMAX cry, I am so much better than those idiots, I know, to get the sound right, whatever that is in my very eccentric mind. So I must endorse, that you tell people, do it your own way, good luck with Macondo cloning, I agree, it cannot be done, too many Romy inseminations in there.

The most serious impasse between topologies of yours/mine is electricity use; makes me have so many of the completely ridiculously inexpensive Class D amps, that simply kick ass. (Here we go, cat fight again?)

I've also read your miny me writings, and could not stop reading and laughing until 4 am. How can I not like what you have tried, and sometimes failed at? No big deal, it is life, and we are lucky to afford to pursue it, for sure. And my new systems are (they have to be) ecologically "reasonable", and yes Romy, electricity must be saved and many other resources, if we can help with it. I know you will tear a strip of my CAnadian Bacon now, but I would expect a cat to expose the claws once in a while, so I am wearing a helmet and protective clothing, go ahead. And if I have to, my mountain bike is close by to escape this cat attack.

The real quest matters in our personal minds and emotions only, and does not need any endorsement, (perhaps from a favorite wife?) and you cannot copy or clone my life audio quest, in any way, shape, form, intent, or purpose. Or sadly, and certainly, Romy's extremely complicated attempts. I had thought most would know that, but j. is just smarter than the rest? Yes, a fact of audio news, it is.

Posted by decoud on 08-22-2009

It is true, Romy, that the Macondo is not *just* a set of horns and drivers, but nonetheless it *is* a set of horns and driver without which it is impossible to give body to the ideas that you talk about. Someone who has not heard the S2, for example, in the way in which you suggest one uses it, would be hard pressed to achieve the same result simply by following what you say. To navigate anywhere in the space of reproduction possibilities we need not just intelligence and musical sensitivity but tangible landmarks: imitation is therefore inevitable, it seems to me, at least for those who do not live near you and cannot hear directly what it is you are describing. It is not sufficient, but it is necessary.

I should add, incidentally, that the "lite" moniker came from the relative lightness of the horns, not any levity in the intention behind them.

Rgds, D

Posted by Romy the Cat on 08-22-2009

decoud wrote:
…. but nonetheless it *is* a set of horns and driver without which it is impossible to give body to the ideas that you talk about. Someone who has not heard the S2, for example, in the way in which you suggest one uses it, would be hard pressed to achieve the same result simply by following what you say….

Yes, I understand what you were talking but in your reply there is a moment that I find interning. What I am taking about S2, 6C33C, 3A3, Studio 8M, Tannoy Red or anything else that has a definitive meaning then people feel that they know what I am taking about (even if they do not) But when I am implying “proper, meaningful and objective sound evaluation techniques”, the techniques that were responsible for whatever happen with Macondo, then I am very confident that not a lot of people out there have any clue what conversation is all about. A name of specific driver used for a given channel in fact has very little meaning for “ Macondo's Axioms ”. There is something else that is more important: how a given selected driver fulfills owner’s expectation for the channel functional duty.

A few years back I wrote somewhere that I “developed” a semi-mathematical formula according to which an acoustic system’s result might be absolutely objectively weighed up. I did not go very far with advisement of this equation of mine (because multiple reasons) but some of tangentially-derived conclusions from the equation are related to the subject of selected drivers for Macondo. So, if you guys take the subject of building your acoustic systems seriously then I might put some articles about “proper, meaningful and objective sound evaluation techniques” that I developed during the Macondo inventions.

The Cat

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